There is a need in the art for fast, bright, low-powered actuated displays. Displays built from mechanical light modulators are an attractive alternative to displays based on liquid crystal technology. Mechanical light modulators are fast enough to display video content with good viewing angles and with a wide range of color and grey scale. Mechanical light modulators have been successful in projection display applications, and have recently been proposed for direct view applications. Specifically there is a need for mechanically actuated displays that use mechanical light modulators and can be driven at high speeds and at low voltages for improved image quality and reduced power consumption.
A mechanical light modulator comprises a shutter and a plurality of actuators. The actuators are used to move the shutter from one state to another state. Of the two states, one can be a state where light is transmitted and another state where light is blocked. The shutter is suspended above a substrate by a plurality of compliant beams, and the actuators are also formed using compliant beams. A display is formed by fabricating an array of mechanical light modulators on a substrate. The compliant beams are attached to the substrate with anchor structures.
The anchor structures need to be sufficiently stiff to limit undesired deflections of the actuators and of the shutter. An example of an undesired deflection would be a deflection towards or away from the substrate for a shutter that is designed to move parallel to the substrate. Such a deflection can occur due to mechanical shock applied to the shutter or due to attraction between the shutter and the substrate. A deflection can also be caused by stresses in the films that are used to form the shutter, the actuators, and the anchors
A need exists in the art for an anchoring structure for these compliant beams that can be built using MEMS fabrication techniques while at the same time preventing or minimizing any undesired beam or shutter deflection.